Process of making printing-plates.



T. S. FOX. 7 moms OF MAKING PRINTING PLA ES. APPLICATION FILED MAY M. 1908.

l ,OG8,023, Patented Nov. 7, 1911.

W'z'Znesses nuenzor;

Eamaaj 1Z5 s I32 -53 i TEIGMAS S. FOKfOE I'lEli" YQEK,

PROCESS OF MAKING PRINTIllG-PLATES.

Specification of mosses.

Application filed ma 14,

To (ZZZ whom it may concern:

lle it known that l'. Tnowus S. Fox. of the borough or", Brooklyn, city and State 5' or in part from the use or" the invention disjamin Day on April slnnle does not, according to this invention,

closed in Patent No. 214393 granted to Ben- 22, 1879. Such facconstitute the actual printing snrtace,'since the fac-si'niile is made upon the face of a suitable transparent medium which is thereafter converted into a negative and this negative is photographically printed upon the plate subsequently etched, inked and pressprinted in the usual manner, or otherwise treated to form a printing surface In the drawing accompanying the present specification Figure 1 is representative in a general way of a design prepared upon a transparentmedium. Fig. 2 is a view of the same medium after the material used in pre paring the design and background has been treated according to the present invention in i8, manner such that the opaque parts of the design are rendered less opaque or in fact transparent and the transparent parts less transparent or in fact opaque.

lnicarrying my invention into practice, a suitable medium which may afterward he used as a negative is first provided. T his medium such as 2 may he of various materials. For instant-ail; may consist. of a film of collo dion, pyroxylin. PQlfilllll. or a glass plate covered with suitable ink-receiving transparent material. Under this medium I place a suitable outline sketch hzue print,

etc., of the form, picture or other article, comprehensively called design. illuminated by transmitted or reflected light; and properly produce the design (such production flbeing here designated in a general'way by 3) into a negative, that is to say those portions Letters-Patent.

Serial Ha. $32,888.

of the medium which are inked and opaque are thereby rendered transparent translucent or similarly modified and cmiversely-v the transparent parts of the medium are rendered transparent or opaque;

l do not wish to limi i'nysel-f to any par ticular details or materials for eii'ectling -this result I have, however, devised one practical method for the purpose which will now he described; that is to say, I dust. finely powdered asphaltum overthe inked impressions on the medium and after removing the loose non-a lherent surplus, I apply over the entire surface with 'a brush a washing of Higginss Waterproof black inlr which ads heres to the parts of the medium not covered by the ink previouslv applied to the medium as aforesaid. A :tter drying, a suitable reagent such as lienzin, or similar solvent, is applied vhirh dissolves the asphaltum-inlr parts of the surface and yieldsjn consequence the negative already referred to. From this nt grative after drying prints may he photo- {graphically taken upon sensitized surfaces which may he etched, or otherwise prepared ito form a printing; plate afterward pressiprinted i the usual manner. Not only am I thus (Qnahlcd to utilize the well known printmg E a-tented Nov. '2, il lli.

nlm with its inherent advantages and facility of operation under circumstances and for purposes LG which the film was heretofore altogether or extremely ditlicult or practical application. but many incidental advantages are involved in the utilization of the present proeess'whieh will he appreciated by those familiar with the For instance. in the Zinc plate process of engrav ingwith its diiliculty and inconvenience of transferring the proper depth and tone values from a printing film onto a more or less illegible design etched on a zinc plate th re introduced an equivalent transfer onto a transparentniecliuzn heneai i. which is the illuminated design,- u loreorer, it e31 ables the printing film or analogous methods of preliminary preparation to be readily used in connection with the. production of Man 0721' i printing Li-mung the n1eupun the i 4}, and. 1; pnoioggrzzp 1 1g phi: [r0112 The? medium so prehunted and acied upun.

22. A pmcv s for the 331M? cm. of phototclwd 'mmg plates, the me consisting in {Hep-Luring the dcsign Jn in an a transparent mediunn in the! dust-in powdered :mphaiium aver the me ...um and removing;

the surplus, in then applying a Washing 0' H' "@1131; water nruof ink to (he medium, in

t1: '1 app v1 a suitable solvent for the purpose Q'Jlllild and ir 511g: the medium, and

J1 iestimon 'wl'm'uof I have signed my 11211210, to this 1 cificzfi' m in the presence of two subscribing wit .LOSSzlS.

THOMAS S; FTC-X.

"EVER, 

